Current practice in the USA for inoperable esophageal cancer is a palliative treatment using metal stent for end-stage cancer patients. Outside the USA (especially in far east countries including China and Korea), there have been reported clinical benefits of attaching sealed sources such as prostate seeds to the outside of an esophageal stent. Although simple and preliminary, such radioisotope sources had doubled the mean survival period with high statistical confidence. The investigators have demonstrated the feasibility of an advanced radioactive esophageal stents that will maximize dose to the tumors and significantly shorten the dose delivery time to more quickly achieve maximized clinical benefits. A broader collaboration has been established among stent manufacturer, surgical experts, leading dosimetrist, and regulatory professionals for the development of radioactive esophageal stents. The ultimate goal is to improve treatment efficacy by matching radiation dose distribution to tumor distribution. The specific aims include (1) device safety demonstration of radioactive esophageal stents; (2) obtaining 510(k) FDA clearance. The Phase II research will begin with in vivo biocompatibility assessment and end with preliminary clinical assessment using the proposed advanced radioactive esophageal stents.